By using clang-format directives 'IncludeBlocks' and 'IncludeCategories'
headers are regrouped by categories:
1. "cmConfigure.h" which must be first
2. header matching current implementation file
3. standard language headers
4. CMake replacement ones
5. external headers (i.e. #include directive with '<' and '>')
6. Qt headers
7. cmsys/* headers
8. cm_* headers
9. CMake headers (i.e. starting with 'cm[A-Z]')
10. all other headers
Fixes: #19674
